Telltale for electric lights.



J. F. KEY. TELLTALE FOB ELECTRIC LIGHTS. APPLIGATION FILED DBO. so, 1908.

Patnted June 27,1911.

: earns arm We JAMES FRANK KEY, OF WASHINGTON, DISTRICT OF COLUMBIA.

TELLTALE FOR ELECTRIC LIGHTS.

Specification of Letters Patent. Patented June 2'? 1911, Application filed December 30, 1908.

Serial No. 469,959.

dicatin the operative condition of an electric lig t.

The object of the invention is to produce an arrangement for use in connection with ships runnin lights, .or other lights of which the continuous operation is important,

the arran ement being such that any failure of such lights, whether due to lack of current or to lnternal causes in the lamps or in their circuits, shall be disclosed with certainty by means of devices distant from such lamps.

The invention consists in the use, for the purpose before described, of telltale-lamps,

lights and telltale-lamps arranged in accordance with the present invention; Fig. 2 is a these telltale-lamps being arranged in shunt with the primary lamps of which they are to indicate the condition, and having such resistance that, during normal operation, they glow dimly. In the case of .a failure of current the telltale-lam s are extinguished,

while in the-case of failure in the primary lamps, due to breakage or burning out or similar causes, the telltale-lamps low brightly. In either case the; failure 0 the primary lamps is indicated.

In the drawings: Figure 1 is a diagrammatic plan view of a ship having running diagram of the wiring connections of the arrangement shown in Fig. 1; and Fig. 3 is a diagram of another method of connecting the lamps.

As shown in Fig. 1, the running lamps on the vessel 1 comprise a masthead light 2, a stern light 3, a port side-light 4, and a starboard slde-light 5. The telltale-lamps corresponding to these running lights are lo-;

cated for convenience upon the brid e of the vessel and are designated as 10, 9, and 8, respectively.

As shown in Fi 2, the running lights 2 and 3 are connected in series with each other and with a source of current 11, which may be a dynamo or other suitable source, the

circuit passin from the dynamo, through a' wire 22, to' a amp 2, thence, through a wire 14, to the lamp 3, and thence, through wires 16 and 23, back to the dynamo. The running lights 4 and 5 are also connected in series with each other in a branch circuit in multiple with the circuit through the lamps 2 and 3. This branch circuit passes from the wire 23, through a Wire 24, to the lamps 4 and 5, and back from the latter, through a ,w1re25, to the wire 22, and thus to the dynamo.

Br idging each primary light is a shunt circuit including the corresponding telltalelamp. Thus the telltale-lamp 10 is included in a shunt circuit 15 around the light 2, the telltale-lamp 9 is included in a shunt circuit 17 around the light 3, the telltale-lamp 7 is in a shunt circuit 19 around the lamp 4, and the telltale-lamp 8 is in a shunt circuit 21 around the lamp 5.

As an example of suitable electric lamps for the purpose in question, the running llghts may be 50 volt lamps of 32 candlepower, and the tell-tale lamps ma be 125 volt lamps of 2 candle-power eac During the normal operation of the system, the

telltaledamps, owing to their much higher or burns out, the corresponding telltale-lamp will then receive all of the current in the corresponding circuit, and the resulting increase in its brilliancy will indicate the extinction of the primary light. The same thing will result in the case of a break in the portion of the circuit bridged b any of the shunt-circuits through the tellta e-lam s. As a further precaution, in connection with the arrangement just described, the binnaole-lamp 6 may be used as a supplementary telltale device. "This lamp is shown as connected in a shunt-circuit 13 which 'is bridged across a resistance 12 introduced in the main conductor 22. The resistance 12 diverts a sufiicient amount of current through the binnacle-lamp to cause the latter to glow normally, but, in case of the extinction of any of the primary lamps, the current through the main conductors is diminished and the binnacle-lamp then glows less bri htly or 1 becomes dark. -This arrangement 0- the innacle-lamp does not constitute a part of the present invention, and is not claimed herein. I

Fig. 3 shows another arrangement of the circuits which differs from that of Fig. 2 in'ahaving the primary lights in series in a single circuit, each primary light being in shunt with the corresponding telltale-lamp, as previously described. The several wires in this figure are numbered similarly with the corresponding wires in Fig. 2, the lead wires'of the primary lamps 2, 3, 4 and 5 bei designated by the reference numbers 14, 16, 18 and 20, respectively, while the lead wires of the corresponding telltale-lamps are designated as15, 17, 19 and 21, respectively. In this figure the binnacle-lamp is also-arranged in connection with the telltale in the same manner as-in Fig. 2. The operation of the telltale-lamps in this a'rrangement is substantially the same as in the parallel arrangement of Fig. 2. v v While, for the sake of economy, it is preferable to use telltale-lamps of muchlower candle-power than the primary lamps, the

invention, in its broadest aspects, is not lim- 3 .ited to this feature, but resides broadly in the use of a telltale-lamp in shunt with the primary lamp and adapted normally to glow with less than its full rated brilliancy.-

What I claimis: v 1. The combination of a li hting circuit,

comprising a primary incan escent electric lamp, a shunt around said lamp, and a telltale lamp in said shunt having a specific rcsi $ance such a t adallt it tabum-l-dimly when the primary lamp. is in normal condition.

2'. The combination of a li htingcircuit, comprising 'a primary incan escent' electric lamp, ashunt around saidlamp, and a.tell tale lamp in said shunthaving a lower candle-power-and a higher resistance than the primary lamp, whereby the telltale lamp normally will burn dimly but will burn brightly when the primary lamp is eatinguished.

- 3. The c ombination of a lighting circuit,

comprising a primary incandescent electric lamp,a second primary incandescent lamp inseries therewith, :a telltale incandescentv lamp in multiple with the first..primary lamp and in series with the second primary lamp, the said telltale being of higher resistance and of lower candle power than said primary lamps, a second telltale incandescent lamp in series with the first primary lamp and in multiple with the second pr1- mary lamp, the said second telltale lamp being of higher resistance and, of lower candle power than the said primary lamps, whereby the'telltale lamps burn dimly when the primarylamps are l1t, and when one of the primary lamps burns out, the other. is

also extinguished and the telltale lamp in multiple with the burned out lamp burns more brightly. 1 g

Y JAMES FRANK KEY,'

'Witnesses:

p v I THOMAS DURANT, "ALICE M. KITCHEN. 

